Microcirculatory Status and Metabolic Activity of Tissues after Local Administration of Autologous Plasma on the Model of Explosive Soft Tissue Wound in Rats

Background. The possibility of local application of autologous blood plasma (ABP) in soft tissue injuries is currently of particular interest.Objectives. Evaluation of the effects of peri-wound (perifocal) administration of ABP on red blood parameters, microcirculation and oxygen supply of soft tissues of the limb in experimental explosive wound (EW) in rats.Methods. EW was simulated on male Wistar rats (n=146) using a firecracker with a pyrotechnic mixture (patent RU No. 2741238 dated 22.01.2021). Animals were divided into 4 groups: control (2), comparison (1), main (1). The volume of blood loss in explosive wounds was 8 and 15% of the estimated circulating blood volume (CBV) of the animal. Blood was drawn from the rat tail to obtain ABP. 3 hours after the injury, ABP or 0.9% sodium chloride solution was injected intramuscularly into the explosive wound area at a rate of 2.0 ml/kg of animal weight. After 3, 7, 14, 28 days, the number of red blood cells, haemoglobin content, haematocrit were determined in the blood, and microcirculation and oxidative metabolism parameters were determined in the skeletal muscles of the injured area. The data were processed using Microsoft Excel 2013 (Microsoft, USA) and Statistica 10.0 (StatSoft Inc., USA).Results. Blood loss of 8% of the CBV in injured animals did not lead to changes in the quantitative composition of peripheral red blood. After an explosive wound with a blood loss of 15% of the CBV, there was a moderate decrease in the number of red blood cells (from 8.3×1012/l to 6.5×1012/l, p < 0.02), haemoglobin level (from 149.5 g/l to 118 g/l, p < 0.01), haematocrit (from 43.8% to 33.6%, p < 0.01) with recovery by day 7 of observation. The explosive soft tissue wound was characterized by marked post-traumatic microcirculatory disorders irrespective of the amount of blood loss. Perifocal intramuscular administration of ABP in animals with an explosive wound and blood loss of 15% CBV reduced the severity of post-traumatic microcirculatory and oxidative metabolic disorders mainly in the early post-traumatic period, as evidenced by an increase in the perfusion variation coefficient Kv by 1.2–1.3 times (p < 0.05), tissue oxygen consumption U by 20–22% (p < 0.05) and fluorescent oxygen consumption by FPC by 48% (p < 0.05).Conclusion. With an experimental explosive wound of the soft tissues of the thigh in rats, a single early (3 hours after the injury) peri-wound intramuscular administration of ABP reduces the severity of local post-traumatic microcirculatory and metabolic disorders in skeletal muscle.